Establishing a New World Screwworm Sterile Fly Barrier Zone in Mexico to Prevent the Further Northern Movement of the Wild Fly to the United States

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) is adjusting its New World screwworm (NWS) sterile fly dispersal strategy to push this devastating pest away from the United States and back toward the previously established biological barrier in Panama.  APHIS is shifting its dispersal efforts to Mexico—the northernmost point of the outbreak—using our scientifically proven eradication model. We successfully implemented this approach in previous eradication efforts, and it remains the most effective strategy.   

APHIS identified two locations for sterile fly dispersal centers in Mexico. As APHIS transitions to these sites, we will continue operations using dispersal centers outside of Mexico to ensure program continuity. By adjusting dispersal locations, we ensure the greatest number of sterile flies are released in the critical areas. While sterile fly dispersal will shift north, APHIS remains committed to working closely with Nicaragua, Honduras, and regional partners to support on-the-ground outbreak response activities, including surveillance, animal health outreach, and early detection efforts.